Alloys containing Cu as the main component are excellent in the characteristics such as electroconductivity, plating property, soldering property, high strength electric conduction, heat-resistance and the like so that they are used for electronic parts and the like.
The hitherto known Cu alloys used for electronic parts were not necessarily satisfactory in their mechanical properties or, particularly, in the hardness, elasticity (resiliency) and the like.
Alloys of high-strenght type with heat-resistance can be obtained by adding Ni, Si, B and the like to an alloy of Cu, Fe and Ti which is turned into any of intermetallic compounds of Cu or Fe with Ni, B or Ti or into a solid solution based on any of them as the parent body, both having the age-hardening property. Such alloys have an excellent characteristic as exemplified by the function of Cu-Fe-Ti alloy or Cu-Ni-Ti alloy as a heat-resistant electroconduction alloy or by Cu-Si-Ti alloy as heat-strength electric conduction alloy.
That is to say, by adding any of third elements to such an alloy, Fe turns into Fe.sub.2 Ti in the case of Cu-Fe-Ti and Ni turns into Ni.sub.3 Ti in the case of Cu-Ni-Ti.
Si is provided with the age-hardening property in the form of Si.sub.3 Ti.sub.5 in the case of Cu-Si-Ti.
The present invention has been made paying attention to the above respects and provides a Cu alloy suitable as the material for electronic parts.